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Live flood monitor

Real-time river flooding
across America.

Live USGS streamgauge readings, FEMA flood zones, NWS flood watches and warnings, and historical context — one map, refreshed throughout the day. Built for flood researchers, emergency managers, and outdoor recreationists.

Last updated September 26, 2026 · 149 sensors live
Rivers above flood
47
Watersheds elevated
98
Active flood sensors
149
USGS gauges tracked
10K+
Layers
Flow vs. normal
< 50%
~ 100%
200%
500%+
Tiles © Mapbox · Data USGS, NOAA NWS, FEMA, NRCS · Click any feature for details · Multiple layers under your click aggregate into one popup.
Today's flood briefing

What's happening right now

An AI-generated daily summary stitched from active streamgauge readings, NWS warnings, and watershed status.

September
26
2026
Flood report
# CRITICAL FLOODING EMERGENCY: Nation Faces Multiple Severe Flood Threats from Hurricanes and Nor'easter

The United States is confronting a dangerous multi-front flooding crisis as Hurricane Nolo threatens catastrophic flooding in Hawaii, Hurricane Polo menaces California's coast, and a powerful nor'easter batters the East Coast with hurricane-force winds and severe coastal flooding. Extreme streamflow measurements across the nation reveal water levels reaching up to 100 times normal capacity in some areas, with communities from the Midwest to Appalachia experiencing dangerous flood conditions. Emergency declarations are in effect across multiple states as officials warn residents to prepare for life-threatening flash floods, mudslides, and prolonged inundation.

The Midwest and Ohio River Valley face particularly dire situations, with communities near Fort Wayne, Indiana experiencing catastrophic conditions as the St. Marys River surges to 10,458% of normal flow. Toledo and surrounding areas along the Maumee River are seeing flows at 2,286% of normal, threatening widespread urban and agricultural flooding. In West Virginia, the town of Elkins faces extreme danger as the Tygart Valley River reaches 1,772% of normal capacity, while Johnstown, Pennsylvania confronts similar threats with the Conemaugh River at 1,613% of normal. Iowa communities are particularly hard-hit, with Des Moines area rivers—including the Des Moines River at 2,009% of normal and the South Skunk River at an astronomical 6,442% of normal—creating emergency conditions that threaten downtown areas, residential neighborhoods, and critical infrastructure.

The Southwest and Pacific regions face compounding threats as New Mexico's Pecos River system explodes to over 102,000% of normal flow near Carlsbad, creating unprecedented flash flood dangers in typically arid communities. Hawaii's Big Island braces for Hurricane Nolo's "catastrophic and life-threatening flooding" with emergency shelters on standby and federal assistance approved. Meanwhile, Southern California coastal communities from Long Beach to Laguna Beach prepare for massive swells and coastal flooding from Hurricane Polo, even as the storm remains offshore near Mexico. The East Coast nor'easter is already causing significant flooding in New Jersey and threatening New York City with 60 mph winds and coastal inundation, prompting states of emergency declarations across the region. Authorities urge residents in all affected areas to avoid travel, move to higher ground if in flood-prone areas, and prepare for extended power outages and road closures.
Right now

Rivers currently flooding or rising

Live USGS streamgauge readings aggregated by river. Percent-of-normal compares current flow to the seasonal average.

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River Observed (cfs) Seasonal avg (cfs) vs. Normal
Black Warrior River 2,070 2,830 73% of normal
Suwannee River 5,420 7,030 77% of normal
Edwards River 423 54 ↑ 783% of normal
Wapsipinicon River 10,900 618 ↑ 1764% of normal
Root River 248 18 ↑ 1378% of normal
Tygart Valley River 11,500 778 ↑ 1478% of normal
Delaware River 1,790 189 ↑ 950% of normal
Olentangy River 741 72 ↑ 1029% of normal
Middle Raccoon River 343 48 ↑ 710% of normal
Nodaway River 1,310 146 ↑ 897% of normal
Pecos River 12,812 174 ↑ 7382% of normal
Mahoning River 2,560 379 ↑ 675% of normal
Shade River 182 8 ↑ 2373% of normal
Blackwater River 208 27 ↑ 762% of normal
Cumberland River 2,850 308 ↑ 925% of normal
Piedra River 1,360 80 ↑ 1711% of normal
Cedar River 19,246 2,243 ↑ 858% of normal
Animas River 3,770 385 ↑ 979% of normal
Tombigbee River 6,705 8,916 75% of normal
Souris River 260 41 ↑ 636% of normal
Purgatoire River 342 9 ↑ 3826% of normal
Dolores River 716 30 ↑ 2371% of normal
Little Colorado River 555 12 ↑ 4625% of normal
Blanchard River 619 60 ↑ 1027% of normal
Teton River 257 16 ↑ 1577% of normal
North Canadian River 556 30 ↑ 1875% of normal
Iowa River 7,970 342 ↑ 2330% of normal
Buckhannon River 1,750 36 ↑ 4868% of normal
Samish River 31 29 106% of normal
Straight River 1,210 93 ↑ 1305% of normal
Gauley River 2,200 125 ↑ 1760% of normal
Chariton River 409 16 ↑ 2509% of normal
Tolt River 379 139 ↑ 273% of normal
Stillwater River 377 43 ↑ 879% of normal
Tiffin River 443 46 ↑ 974% of normal
Scioto River 20,940 1,795 ↑ 1167% of normal
Raccoon River 1,310 193 ↑ 679% of normal
Youghiogheny River 1,105 127 ↑ 869% of normal
Williams River 542 35 ↑ 1549% of normal
Conemaugh River 6,740 386 ↑ 1746% of normal
South Platte River 1,430 191 ↑ 751% of normal
Cranberry River 347 20 ↑ 1735% of normal
Blue Earth River 1,800 164 ↑ 1098% of normal
Maumee River 17,780 778 ↑ 2287% of normal
Green River 384 463 83% of normal
Casselman River 707 90 ↑ 790% of normal
Middle Fork River 760 18 ↑ 4222% of normal

47 rivers are running elevated right now. Create a free account to see the full list, follow your rivers, and get alerts.

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By basin

Watersheds running elevated

Aggregated by HUC8 watershed code. Useful for catchment-level flood-risk assessment.

CSV FREE ACCOUNT
HUC8 code Watershed Observed (cfs) vs. Normal
h03110205 Lower Suwannee 5,420 77%
h12040104 Buffalo-San Jacinto 204 ↑ 2914%
h10030203 Marias 257 ↑ 1577%
h05030106 Upper Ohio-Wheeling 299 ↑ 1208%
h11080008 Revuelto 295 ↑ 4476%
h02050201 Upper West Branch Susquehanna 2,360 ↑ 731%
h03180002 Middle Pearl-Strong 435 ↑ 7909%
h03080103 Lower St. Johns 150,771 109%
h03080101 Upper St. Johns 2,710 58%
h07080104 Flint-Henderson 583 ↑ 792%
h07080103 Lower Wapsipinicon 10,900 ↑ 1764%
h07100009 Lower Des Moines 17,000 ↑ 2009%
h07100008 Lake Red Rock 489 ↑ 2919%
h07100004 Middle Des Moines 5,700 ↑ 1061%
h07100007 South Raccoon 343 ↑ 710%
h07100006 North Raccoon 1,310 ↑ 679%
h06010101 North Fork Holston 1,380 ↑ 746%
h04100011 Sandusky 530 ↑ 4818%
h05050005 Gauley 3,089 ↑ 1716%
h05050007 Elk 1,200 ↑ 2182%
h05040001 Tuscarawas 858 ↑ 1569%
h14080104 Animas 4,020 ↑ 948%
h14080102 Piedra 1,360 ↑ 1711%
h14080101 Upper San Juan 2,152 ↑ 1140%
h17110004 Nooksack 227 ↑ 741%
h17110002 Strait Of Georgia 31 106%
h15020016 Lower Little Colorado 555 ↑ 4625%
h07040002 Cannon 1,210 ↑ 1305%
h04100004 St. Marys 2,280 ↑ 10459%
h04100005 Upper Maumee 6,680 ↑ 2646%
h05010008 Kiskiminetas 1,020 ↑ 1283%
h05010007 Conemaugh 7,276 ↑ 1613%
h05010006 Middle Allegheny-Redbank 915 ↑ 839%
h04100008 Blanchard 619 ↑ 1027%
h04100009 Lower Maumee 11,100 ↑ 2114%
h04040002 Pike-Root 248 ↑ 1378%
h02050304 Lower Juniata 527 ↑ 702%
h02050303 Raystown 1,657 ↑ 692%
h03160113 Lower Black Warrior 2,070 73%
h18070102 Santa Clara 398 ↑ 4270%
h05020006 Youghiogheny 1,812 ↑ 837%
h05020004 Cheat 208 ↑ 762%
h05020002 West Fork 1,060 ↑ 1491%
h14030003 San Miguel 160 ↑ 1905%
h14030002 Upper Dolores 716 ↑ 2371%
h05020001 Tygart Valley 28,410 ↑ 1772%
h07080205 Middle Cedar 18,949 ↑ 945%
h07080207 Upper Iowa 432 ↑ 1291%
h18070203 Santa Ana 338 ↑ 3189%
h07080201 Upper Cedar 813 ↑ 707%
h07120004 Des Plaines 3,464 ↑ 1255%
h07080208 Middle Iowa 8,779 ↑ 2168%
h07080209 Lower Iowa 783 ↑ 2034%
h03160106 Middle Tombigbee-Lubbub 975 70%
h12030108 Richland 466 ↑ 5210%
h05080001 Upper Great Miami 551 ↑ 777%
h13060001 Pecos Headwaters 11,650 ↑ 102643%
h10280201 Upper Chariton 409 ↑ 2509%
h13060008 Rio Hondo 241 ↑ 10955%
h13020203 Rio Grande-Albuquerque 577 ↑ 4808%
h10240010 Nodaway 1,310 ↑ 897%
h11100301 Middle North Canadian 556 ↑ 1875%
h10200203 Salt 1,010 ↑ 842%
h18100200 Salton Sea 321 ↑ 1084%
h17110010 Snoqualmie 999 ↑ 424%
h07020011 Le Sueur 3,230 ↑ 3713%
h17110013 Duwamish 384 83%
h10270102 Middle Kansas 296 ↑ 5861%
h10270103 Delaware 1,790 ↑ 950%
h05030103 Mahoning 2,560 ↑ 675%
h02070001 South Branch Potomac 225 ↑ 776%
h07080107 Skunk 329 ↑ 2632%
h13020211 Elephant Butte Reservoir 1,380 ↑ 1758%
h07080105 South Skunk 728 ↑ 6442%
h07090006 Kishwaukee 163 ↑ 12538%
h07090002 Crawfish 188 ↑ 620%
h03160201 Middle Tombigbee-Chickasaw 5,730 76%
h05040006 Licking 303 ↑ 2090%
h10190003 Middle South Platte-Cherry Creek 1,430 ↑ 751%
h10190004 Clear 270 ↑ 2288%
h07020009 Blue Earth 1,800 ↑ 1098%
h11120103 Upper Prairie Dog Town Fork Red 1,670 ↑ 18764%
h05060002 Lower Scioto 11,693 ↑ 1188%
h05060003 Paint 3,916 ↑ 3402%
h05060001 Upper Scioto 11,542 ↑ 1190%
h05130101 Upper Cumberland 2,850 ↑ 925%
h13060011 Upper Pecos-Black 1,162 ↑ 716%
h09010003 Lower Souris 260 ↑ 636%
h11020010 Purgatoire 342 ↑ 3826%
h04100006 Tiffin 443 ↑ 974%
h05030204 Hocking 169 ↑ 966%
h05030201 Little Muskingum-Middle Island 281 ↑ 1713%
h05030203 Little Kanawha 1,203 ↑ 8413%
h05030202 Upper Ohio-Shade 182 ↑ 2373%
h13010001 Rio Grande Headwaters 384 ↑ 662%
h05130202 Lower Cumberland-Sycamore 4,860 ↑ 607%
h17110012 Lake Washington 77 ↑ 285%
h07130001 Lower Illinois-Senachwine Lake 323 ↑ 2212%

98 watersheds are running elevated. Create a free account to see every basin.

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Background

What causes river flooding

Flooding is rarely a single-cause event — multiple factors usually compound. The most common drivers across the U.S.

🌧

Heavy rainfall

Persistent rain saturates soils and overwhelms drainage networks. Tropical systems and atmospheric rivers are the worst culprits.

⛄

Rapid snowmelt

Spring melt pulses can deliver months of accumulated water in days — especially when warm rain falls on existing snowpack.

🧊

Ice jams

Breakup ice can block channels, forcing water to back up and inundate upstream banks. Common on northern rivers in early spring.

🌊

Storm surge

Coastal hurricanes push seawater inland. Surge combined with rainfall is the deadliest flood scenario in U.S. history.

🛡

Reservoir releases

Controlled dam releases can dramatically increase downstream flow. USACE and USBR publish release schedules, but conditions change fast.

🌌

Burn scars

Wildfire-stripped slopes can't absorb rainfall — even modest storms produce dangerous flash floods on burned watersheds for years afterward.

Safety

Flood preparedness checklist

Floodwaters rise faster than most people expect. The basics that save lives.

1
Never drive through floodwaterSix inches can stall a car; two feet floats most vehicles. Turn around — don't drown.
2
Monitor levels near youTrack the gauges upstream of your location. Snoflo's push alerts can ping you the moment a threshold is crossed.
3
Have an evacuation planKnow two routes out and where higher ground sits. If officials issue an evacuation order, leave — don't wait.
4
Move valuables upDocuments, electronics, and sentimentals to upper floors. Disconnect electrical at the main breaker if water enters the structure.
5
Trust official sourcesNWS warnings and local emergency management are the authoritative source. Snoflo data is informational; always cross-check.
6
After the water recedesDon't return until officials clear the area. Floodwater carries sewage, fuel, and downed power. Document damage before cleanup.
Frequently asked

Flood map & river monitoring FAQ

What does "percent of normal" mean?

The current flow at a gauge compared to its seasonal average for this date. 100% means flow is right at the historical norm. 200%+ means twice the typical flow — a strong indicator of flood conditions on small-to-medium rivers. Every gauge-level flow report shows its live percent-of-normal.

What's the difference between a flood watch and a flood warning?

Watch: conditions are favorable for flooding within the next 12–48 hours. Warning: flooding is happening or imminent. Both come from the National Weather Service. Snoflo overlays both as toggleable layers on the map above.

How often does Snoflo's data refresh?

USGS streamgauge readings update every 15 minutes; we re-pull every hour. NWS warning polygons update as the NWS issues them — usually within 5 minutes. FEMA flood zones are static (the National Flood Hazard Layer is updated quarterly).

What is the FEMA flood zone layer?

FEMA's National Flood Hazard Layer (NFHL) shows the 1%-annual-chance ("100-year") and 0.2%-annual-chance ("500-year") floodplains. These are based on long-term hydrologic modeling, not current conditions. Useful for property risk; not a real-time signal.

Can I get an alert when my local river floods?

Yes. Save any USGS gauge as a favorite in the Snoflo iOS app, set a threshold (e.g. "alert me at 20 ft stage"), and you'll get a push the moment it crosses. Free with a Snoflo account.

Is Snoflo a substitute for official warnings?

No. Snoflo is informational. For life-safety decisions always follow guidance from local emergency management, the NWS, and law enforcement.

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